Introduction This third study in the Sonography in Hypotension and Cardiac Arrest in the Emergency Department (SHoC-ED) series examined potential relationships between point-of-care ultrasound (PoCUS) use and the length of resuscitation, the frequency of interventions, and clinical outcomes during cardiac arrest. Methods A health records review was completed for adult patients (>19 years, without a do not resuscitate (DNR) order) who presented to a tertiary emergency department in cardiac arrest between 2010 and 2014. Patients were grouped based on PoCUS use and findings for cardiac activity. Data were analyzed for length of resuscitation, frequency of interventions, return of spontaneous circulation (ROSC), survival to hospital admission (SHA), and survival to hospital discharge (SHD). Results Of the 223 patients who met inclusion criteria, 180 (80.7%) received assessment by PoCUS during cardiac arrest management in the emergency department (ED). In the PoCUS group, 21 (11.6%) demonstrated cardiac activity and 159 (88.4%) did not. Patients with activity on PoCUS had longer mean resuscitation times (27.3; 95% confidence interval 17.7-37.0 min) than patients with no activity (11.51; 10.2-12.8 min) and patients who did not receive a PoCUS exam (14.36; 9.89-18.8 min). Patients with cardiac activity on PoCUS were more likely to receive endotracheal intubation (ET; 95.23%; 86.13-104.35%) and epinephrine (Epi; 100%; 100-100%) than patients with no activity (ET: 46.54%; 38.8-54.3%; Epi: 82.39%; 76.50-88.31%) and those with no PoCUS (ET: 65.11%; 50.87-79.36%; Epi: 81.39%; 69.76-93.03%). Those with no cardiac activity on PoCUS were much less likely to achieve ROSC (19.5%; 13.4-25.6), SHA (6.9%; 2.97-10.86%) and SHD (0.6%; -0.5-1.8%) compared to those with cardiac activity on PoCUS (ROSC; 76.19%; 57.97-94.4%), SHA (33.3%; 13.2-53.5%), SHD (9.5%; -3-22.07%), and those with no PoCUS (ROSC 39.5%; 24.9-54.1%; SHA 27.9%; 14.5- 41.3%, and SHD 6.9%; -0.6-14.59). Conclusions Emergency department cardiac arrest patients with cardiac activity on PoCUS received longer resuscitation with higher rates of intervention as compared to those with negative findings or when no PoCUS was performed. Patients with cardiac activity on PoCUS had improved clinical outcomes as compared with patients not receiving PoCUS, and patients with no activity on PoCUS.

ObjectivesPoint-of-care ultrasound (POCUS) is used increasingly during resuscitation. The aim of this study was to assess whether combining POCUS and electrocardiogram (ECG) rhythm findings better predicts outcomes during cardiopulmonary resuscitation in the emergency department (ED).MethodsWe completed a health records review on ED cardiac arrest patients who underwent POCUS. Primary outcome measurements included return of spontaneous circulation (ROSC), survival to hospital admission, and survival to hospital discharge.ResultsPOCUS was performed on 180 patients; 45 patients (25.0%; 19.2%–31.8%) demonstrated cardiac activity on initial ECG, and 21 (11.7%; 7.7%–17.2%) had cardiac activity on initial POCUS; 47 patients (26.1%; 20.2%–33.0%) achieved ROSC, 18 (10.0%; 6.3%–15.3%) survived to admission, and 3 (1.7%; 0.3%–5.0%) survived to hospital discharge. As a predictor of failure to achieve ROSC, ECG had a sensitivity of 82.7% (95% CI 75.2%–88.7%) and a specificity of 46.8% (32.1%–61.9%). Overall, POCUS had a higher sensitivity of 96.2% (91.4%–98.8%) but a similar specificity of 34.0% (20.9%–49.3%). In patients with ECG-asystole, POCUS had a sensitivity of 98.18% (93.59%–99.78%) and a specificity of 16.00% (4.54%–36.08%). In patients with pulseless electrical activity, POCUS had a sensitivity of 86.96% (66.41%–97.22%) and a specificity of 54.55% (32.21%–75.61%). Similar patterns were seen for survival to admission and discharge. Only 0.8% (0.0–4.7%) of patients with ECG-asystole and standstill on POCUS survived to hospital discharge.ConclusionThe absence of cardiac activity on POCUS, or on both ECG and POCUS together, better predicts negative outcomes in cardiac arrest than ECG alone. No test reliably predicted survival.

Disease transmission by insect vectors will depend on integrated physiological responses to interacting environmental variables. We explored how interactions between temperature and sucrose concentration affected immunity and fecundity, two variables that contribute to vectorial capacity, in Culex pipiens Linnaeus, 1758 mosquitoes. We provided female C. pipiens with either 2% or 20% sucrose and exposed them to low (22 °C), moderate (25 °C), or high (30 °C) temperatures for 8 days. We then measured the strength of the melanization response in one subpopulation of females and the number of eggs laid as a measure of fecundity in another subpopulation. Temperature interacted with diet to weaken immunity under 2% sucrose at 22 and 25 °C. This effect disappeared at 30 °C, suggesting that high temperatures allowed mosquitoes to compensate for the effects of decreased sucrose. Conversely, increasing temperature increased egg production on a diet of 20% sucrose, but heat exposure on a diet of 2% sucrose decreased fecundity. Overall, we suggest that heat exposure requires investment in thermal protection, which may prompt reconfiguration of the immune system and (or) decreased investment in reproduction. Thus, our understanding of the effects of climate change rest on which physiological system we measure and under which combinations of stressors.

IntroductionElectrocardiographic (ECG) rhythms are used during advanced cardiac life support (ACLS) to guide resuscitation management. Survival to hospital discharge has been reported to be better for patients with pulseless electrical activity (PEA) than asystole in out-of-hospital arrests. Despite this, treatment for these two (non-shockable) rhythms is combined in ACLS guidelines. This study examines if the recorded cardiac rhythm of asystole or PEA during ACLS accurately predicts mechanical cardiac activity as determined by point-of-care ultrasound (PoCUS).MethodsA database review was completed for patients (> 19 years without a do not resuscitate (DNR) order) who presented to a tertiary emergency department in PEA or asystolic cardiac arrest between 2010 and 2014. Patients were separated into two groups: those with electrical cardiac activity (PEA) and those without (asystole). We compared ECG rhythm and PoCUS-documented cardiac activity results (both initial and any) for each case.Results A total of 186 patients met the study criteria. The 46 patients with PEA on ECG were more likely to have cardiac activity than the 140 patients with asystole (odds ratio 7.22 (95% confidence intervals 2.79-18.7) for activity on initial PoCUS; odds ratio 5.45 (2.49-12.0) for activity on any PoCUS during arrest).ECG alone was poorly sensitive for initial cardiac activity (63.64%; 40.66% to 82.80%) and any cardiac activity (54.29%; 36.65% to 71.17%), with specificity marginally better at 80.49% (73.59% to 86.25%) for initial and 82.12% (75.06% to 87.87%) for any activity.ConclusionOur results suggest that ECG rhythm alone is not an accurate predictor of cardiac activity. This supports the use of PoCUS during cardiac arrest, in addition to ECG, to identify patients with ongoing mechanical cardiac activity and to help determine appropriate treatment for this group.